New LED box project

 22 ws2811 LEDs

1 Arduino Uno

connect green wire of LEDs to pin 5

connect red wire of LEDs to +5V

connect white wire of LEDs to GND

Connect USB cable to Arduino

Call up Arduino IDE software

select correct board (Tools/Board

select correct Port (COM 4 in my case)

verify and upload code:

all should work now

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#include <FastLED.h>

#define LED_PIN      5

#define NUM_LEDS     22

#define LED_TYPE     WS2811

#define COLOR_ORDER  RGB

#define BRIGHTNESS   128

CRGB leds[NUM_LEDS];

const CRGB colours[] = {

  CRGB::Red,

  CRGB::Orange,

  CRGB::Yellow,

  CRGB::Green,

  CRGB::Cyan,

  CRGB::Blue,

  CRGB::Purple

};

const uint8_t NUM_COLOURS = sizeof(colours) / sizeof(colours[0]);

const unsigned long FADE_TIME = 5000; // 5 seconds

uint8_t currentColour = 0;

unsigned long fadeStart;

void setup() {

  FastLED.addLeds<LED_TYPE, LED_PIN, COLOR_ORDER>(leds, NUM_LEDS);

  FastLED.setBrightness(BRIGHTNESS);

  fadeStart = millis();

}

void loop() {

  unsigned long elapsed = millis() - fadeStart;

  // Calculate fade progress (0-255)

  uint8_t blendAmount = (elapsed * 255UL) / FADE_TIME;

  if (elapsed >= FADE_TIME) {

    currentColour = (currentColour + 1) % NUM_COLOURS;

    fadeStart = millis();

    blendAmount = 0;

  }

  CRGB current = colours[currentColour];

  CRGB next = colours[(currentColour + 1) % NUM_COLOURS];

  CRGB blended = blend(current, next, blendAmount);

  fill_solid(leds, NUM_LEDS, blended);

  FastLED.show();

  FastLED.delay(20); // ~50 FPS

}

==================================================================